Field of the Invention
The present invention relates to a bicycle seat post height adjustment mechanism and, more particularly, to a bicycle seat post height adjustment mechanism that not only enables said seat post to make fine adjustment, stepless adjustment or stepped adjustment in height, but also allows said seat post to self-return to the assigned position after a user releases the bicycle without holding the seat or the seat post thereof.
Description of the Prior Art
Generally, the height of a bicycle seat post is adjustable so that the user may adjust the seat post to the proper height for comfortable riding according to his/her figure or demands. Substantially, a prior art oil hydraulic bicycle seat post height adjustment device allows stepless adjustments in height so that the seat post is usually adjusted to a too high position or a too low position. Moreover, the user can not adjust the seat post height to the proper height in a mode of fine adjustment or in a mode of stepped adjustment. Therefore, user has to gradually adjust the seat post to modify the height thereof. Further, as the user lifts a bicycle by holding its seat (seat post), the lifting force may impact the prior art oil hydraulic device inside the seat post and thereby cause the seat post displacement in height. Obviously, the prior art bicycle seat post height adjustment device needs to be meliorated.